This invention relates to medicament delivery devices. More specifically, the invention relates to self-administered automatic medicament delivery devices.
Self administered subcutaneous or intramuscular injections are well known in the medical arts and have long been considered standard treatment, such as diabetics, who require fixed or measured doses of medicament on a regular and relatively frequent basis. Further, newer treatments, such as growth hormone injections, also require self administered injections on a regular basis.
Self administered injections considerably decrease the cost of treatment and increase the quality of the patients life by decreasing or even eliminating the need for some visits to the doctor. Self administered injections also provide patients with the opportunity to privately administer their own treatment, without involving third parties, thus giving the patient a sense of independence and control.
Typically, self administered injections are rendered using pre-filled syringes or cartridges of pre-measured doses of medicament. However, such self administered injections suffer from several drawbacks and are particularly ill suited for use by children or patients with disabilities because they required the patient to manually insert an exposed needle in the tissue.
Drug manufacturers also spend significant cost and time producing pre-filled syringes or cartridges. A traditional vial, with a glass body and rubber stopper, is the least expensive and most readily available medicament container system.
Prior art pen injector apparatuses consist of four major components: (i) a pre-filled cartridge or syringe containing the medicament; (ii) a housing formed to receive the pre-filled cartridge or syringe; (iii) a mechanical dispensing assembly; and (iv) a double sided needle assembly that attaches to the receiving housing. Each of the four major components are described in detail below.
Prior art cartridges or syringes consist of a glass or plastic barrel with one open end and an opposite end with either a rubber seal or Luer Lock assembly to receive a needle. A rubber plunger is placed in the open end of the barrel to seal off the assembly slide forward to dispense liquid. Considerable amounts of lubrication, typically silicone, is applied to the plunger and barrel to reduce sliding friction.
Prior art housing assemblies are used to hold the cartridge or syringe in place during and after the injection process. Typically in barrel in shape, the housing has an opening on one end to facilitate receiving the cartridge or syringe. The opposite end has a smaller opening that allows one end of a double ended needle to penetrate a rubber septum in the cartridge, and mounting threads to receive the body of the needle assembly.
Prior art dispensing assemblies typically consist of a barrel shape that attaches to the housing assembly on one end, and a dose setting mechanism on the opposite end. The dose setting mechanism is typically an analog dial or electronic counting system that allows the patient or user to adjust the medicament dose.
Prior art needle assemblies consist of a double ended cannula, which on one end, penetrates the rubber septum of the cartridge seal and on the other end is used to penetrate the subcutaneous or intra muscular space of the human anatomy to deliver the dose. A threaded barrel typically is used to attach the needle assembly to the housing assembly.
Typically, prior art pen injection devices patients or caregivers to manually insert an exposed needle into his or her own tissue. This can be a traumatic experience, particularly for patients requiring frequent or daily injections.
Further, when a patient finishes his or her injection, current injection devices make no provisions for shielding the exposed needle from in advertent sticks. New regulations in certain states now require caregivers to be protected from exposed needles.
In summary, the invention is an automatic medicament delivery device and corresponding method for use with a needle assembly and a vial container that contains a medicament. The device comprises a disposable transfer system and an injector body. The disposable transfer system is configured to enable a user to attach the vial container to the disposable transfer system. The injector body is configured to enable the user to attach the disposable transfer system with the vial container attached thereto to the injector body and to attach the needle assembly to the disposable transfer system after the disposable transfer system is attached to the injector body. The disposable transfer system and the injector body are further configured to cooperatively enable the user to transfer and measure the dose from the vial container into the disposable transfer system after the disposable transfer system is attached to the injector body. The disposable transfer system and the injector body are even further configured to cooperatively enable the user to automatically inject a needle of the needle assembly into the user and deliver the measured dose from the disposable transfer system to the user through the needle. This is done after the needle assembly is attached to the disposable transfer system and when the injector body is pressed against an injection site of the user.